This is a sample Core Flight Software (cFS) project to demonstrate how Trick Variable Server IO can be used.

This project includes two very basic Trick simulations and one basic CFS app. One trick sim is a 'temperature' data producer the other is a consumer. The CFS app, called temp_mon, will monitor the 'temperature' data and send a reset command to reset the data counter. TVS-IO app connects to the Trick Variable Server of each sim, reading and writing values as defined by the *.tvm files. TVS-IO is the messenger that allows the two trick sims to talk to the temp_mon CFS app.

TVS-IO is included as a submodule at apps/tvs_io

At the top level of the repo:

make prep
make install

The sims are located in the trick_sims folder

1. SIM_temp

   This sim is extremely simple. All it does is to count up and reset back to 0 when a reset flag is received. This value is mapped in a *.tvm file to be read by TVS-IO and sent to SIM_range

2. SIM_range

   This sim monitors a value which is set by TVS-IO, and prints it to the console

For both, the same process will build each sim.

cd trick_sims/SIM_...
trick-CP

This command will build the executable, which will be named S_main_<platform>.exe. For example on 64bit linux it might be named S_main_Linux_4.8_x86_64.exe

You will need three terminals, two for each sim and one for cfs

1. Start cFS

   cd build/exe/cpu1
   ./core-cpu1

2. Start each sim:

   cd trick_sims/SIM_temp
   ./S_main_Linux_4.8_x86_64.exe RUN_temp/input.py
   ...
   cd trick_sims/SIM_range
   ./S_main* RUN_range/input.py

If this is your first time running CFS on your machine, you will probably need to increase your message queue limit. If this is the case you should see a message which looks like this when you try to run

Your queue depth may be too large for the
OS to handle. Please check the msg_max
parameter located in /proc/sys/fs/mqueue/msg_max
on your Linux file system and raise it if you
need to or run as root

Increase the limit using

sudo sysctl -w fs.mqueue.msg_max=256 | sudo tee -a /etc/sysctl.conf
sudo sysctl --system

Note this limit is an artifact of how cFS works, it is NOT TVS-IO specific

If everything is running correctly, when CFS is started, you should see a bunch of initialization messages followed by TVSIO periodically attempting to connect to each trick sim.

When each trick sim is started, you should see a succesful connection message. Finally once everything is connected, SIM temp will begin counting